The simple question about self-driving cars we still can’t answer

At a U.S. House subcommittee hearing on self-driving cars Tuesday, Rep. Gregg Harper (R-Miss.) asked a seemingly simple question about what happens when his own car comes upon an autonomous vehicle.

“[If] I honk my horn, will it do any good?” Harper wanted to know.

Mike Abelson, GM’s vice president of strategy, didn’t have an answer. “We haven’t reached that point of deciding how and whether it would be appropriate for vehicles to react and in which way to honking a horn,” he said.

The brief exchange highlights a massive thorn in the side of automakers and policymakers alike: Self-driving cars will have to share the road with human drivers, likely for decades to come. Those vehicles must therefore respond and adapt to the idiosyncrasies and mistakes of humans behind the wheel.